C# Accessing management objects in ManagementObjectCollection

Question

I'm trying to access ManagementObjects in ManagementObjectCollection without using a foreach statement, maybe I'm missing something but I can't figure out how to do it, I need to do something like the following:

ManagementObjectSearcher query = new ManagementObjectSearcher(
     "select Name, CurrentClockSpeed from Win32_Processor");

ManagementObjectCollection queryCollection = query.Get();

ManagementObject mo = queryCollection[0];

score 19 · Accepted Answer · edited Aug 30 '17 at 13:57

19

ManagementObjectCollection implements IEnumerable or ICollection, so either you must iterate it via IEnumerable (ie foreach) or CopyTo an array via ICollection.

However since it supports IEnumerable you can use Linq :

ManagementObject mo = queryCollection.OfType<ManagementObject>().FirstOrDefault()

OfType<ManagementObject> is required because ManagementObjectCollection supports IEnumerable but not IEnumerable of T.

edited Aug 30 '17 at 13:57

C. Ross

31,137
42
147
238

answered Aug 27 '10 at 02:21

Preet Sangha

64,563
18
145
216

2

I needed to add `OfType`... `ManagementObject mo = queryCollection.OfType().First();` – Ryan_S Nov 14 '14 at 03:21
1

I don't see `FirstOrDefault()` in `ManagementObject` either, only `OfType().FirstOrDefault()` worked for me – Jack Apr 25 '16 at 19:30
1

For anyone who is as confused as I was, there's a typo in this answer. It should read: `ManagementObject mo = queryCollection.OfType().FirstOrDefault()` – SGS Jun 01 '17 at 14:58

score 4 · Answer 2 · answered Apr 12 '13 at 07:03

You can not directly call linq from ManagementObjectCollection (nor an integer indexer). You have to cast it to IEnumerable first:

var queryCollection = from ManagementObject x in query.Get()
                      select x;

var manObj = queryCollection.FirstOrDefault();

score 1 · Answer 3 · answered Nov 27 '13 at 00:47

ManagementObjectCollection does not implements Indexers, but yes you can you FirstOrDefault extension function if you are using linq but geeks who are using .net 3 or earlier (like me still working on 1.1) can use following code, it is standard way of getting first item from any collection implemented IEnumerable interface.

//TODO: Do the Null and Count Check before following lines
IEnumerator enumerator = collection.GetEnumerator();
enumerator.MoveNext();
ManagementObject mo = (ManagementObject)enumerator.Current;

following are two different ways to retrieve ManagementObject from any index

private ManagementObject GetItem(ManagementObjectCollection collection, int index)
{
            //TODO: do null handling 

            IEnumerator enumerator = collection.GetEnumerator();

            int currentIndex = 0;
            while (enumerator.MoveNext())
            {
                if (currentIndex == index)
                {
                    return enumerator.Current as ManagementObject;
                }

                currentIndex++;
            }

            throw new ArgumentOutOfRangeException("Index out of range");
 }

OR

private ManagementObject GetItem(ManagementObjectCollection collection, int index)
{
            //TODO: do null handling 

            int currentIndex = 0;
            foreach (ManagementObject mo in collection)
            {
                if (currentIndex == index)
                {
                    return mo;
                }

                currentIndex++;
            }

            throw new ArgumentOutOfRangeException("Index out of range");
 }

C# Accessing management objects in ManagementObjectCollection

3 Answers3